Squares and angle finders measure and transfer angles in building and layout applications. Layout and T-squares gauge straight lines and angles to assist with positioning, marking, and cutting workpieces and materials. Combination and double squares go beyond basic straight line and angle marking for tasks such as laying out perpendicular and parallel lines, checking workpiece and tool alignment, and transferring measurements between materials and machine setups. Angle finders and protractors measure and transfer angles in various construction, carpentry, machining, plumbing, and HVAC applications. Contour gauges copy surface profiles to create a guide for tracing and cutting materials to fit the profile.